Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 6ec917f8f6490861a47f2b03a6065cc1da2be1dc
  - Merge "Improvements in JsonUtilForPnfCorrelationId"
  - Improvements in JsonUtilForPnfCorrelationId

    General fixes and improvements according to the Sonar analysis
    -Added private constructor for a utility class.
    -Refactored lambda expression.

    Issue-ID: SO-1992
    Signed-off-by: Robert Bogacki <r.bogacki@samsung.com>
    Change-Id: Ife8cfdf9c341dc89a1699fd616ec68cba734a5d5

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 2abd30f..6ec917f 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 2abd30fb57643fa07eb1a183c3525d559cb68237
+Subproject commit 6ec917f8f6490861a47f2b03a6065cc1da2be1dc